This invention relates to chopper apparatus and to universal joint apparatus.
One type of spray gun system employs a gun that sprays resin and catalyst and a chopper mounted on the gun for chopping fiberglass and spraying it onto the area that receives the resin and catalyst. The chopper commonly employs an air motor which drives a rubber backup roll. A cutter roll with blades at its periphery, is positioned to roll against the backup roll to cut fiberglass fed between the rolls, but there is often slippage of the cutter roll which prevents the uniform cutting and projecting of fibers. Cost and weight can be saved by eliminating any gear or other connection between the rolls, but there is often slippage of the cutter roll which prevents the uniform cutting and projecting of fibers. Cost and weight also can be minimized by eliminating any muffling device at the exhaust of the air motor, but the air motor often tends to produce a loud and annoying whine sound. A construction which resulted in more reliable rotation of the cutter roll, and also resulted in muffling of the air motor sound, at low cost and without substantial weight increase, would be of substantial benefit to industry.
Where a chopper assembly is fastened to a spray gun, it is generally desirable to provide for limited pivotal adjustment of the chopper both up and down and from side to side. This permits the worker to adjust the chopper to spray fibers at any location with respect to the resin and catalyst spray. Pressured air for the air motor of the chopper is typically supplied through a flexible air hose, with a valve therealong. While flexible hoses are adequate, they tend to clutter the apparatus, and any elimination of flexible hoses or the like is desirable in streamlining the apparatus.